Despite signs that the economy is picking up, the S&P 500 edged down 0.19% last week to 1,192.13 after news that the Securities and Exchange Commission had filed a civil lawsuit against Goldman Sachs. That news caused the entire market to barrel lower Friday.

Pops and drops
Here are the five biggest S&P 500 increases and the five biggest S&P 500 drops of last week (measured Friday close to Friday close):

Winners:

Company

Percent Gain

Goodyear Tire & Rubber (NYSE: GT)

10.9%

Vulcan Materials (NYSE: VMC)

9.3%

DeVry (NYSE: DV)

9.3%

Washington Post (NYSE: WPO)

8.9%

Teradyne

8.8%

Source: Capital IQ (a division of Standard & Poor's).

Losers:

Company

Percent Loss

Goldman Sachs (NYSE: GS)

(10.3%)

Massey Energy (NYSE: MEE)

(9.5%)

Grainger

(8.6%)

Kimco Realty

(7.7%)

United States Steel (NYSE: X)

(7.4%)

Source: Capital IQ (a division of Standard & Poor's).

A closer look
Shares of Goldman Sachs were slammed after the SEC brought a civil lawsuit alleging that the firm had misled investors about securities known as collateralized debt obligations (CDOs). The SEC contends that Goldman did not disclose to investors that its client, hedge fund manager John Paulson, helped pick the risky subprime mortgages that backed the CDOs. At the same time, Paulson -- dubious about the quality of the securities -- bet that the very securities he chose would fall in value.

The lawsuit sheds light on some banks' dealings of securities at the heart of the financial crisis, and has possible repercussions for Goldman and maybe other brokerage houses that engaged in similar trades. The SEC is investigating other mortgage deals underwritten by other banks.

Outside of the Goldman news, shares of Massey Energy continued to fall last week after more than 60 safety violations were found in its mines following a deadly explosion two weeks ago in the coal company's West Virginia mine. This comes on top of a lawsuit filed by the widow of one of the men who died in the explosion, as well as potential lost production.

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Fool contributor Jennifer Schonberger does not own shares of any of the companies mentioned in this article. You can follow her on Twitter. Vulcan Materials is a Motley Fool Inside Value selection. The Motley Fool has a disclosure policy.